


Like a Fire in July

by Inell



Series: Teeny Fic Challenge [19]
Category: Teen Wolf (TV)
Genre: Anal Fingering, Anal Sex, Blow Jobs, Bottom Derek Hale, Bottom Derek Hale/Top Stiles Stilinski, Established Derek Hale/Stiles Stilinski, F/M, Future Fic, M/M, Magical Stiles Stilinski, Marin Morrell/Stiles Stilinski - Freeform, Multi, Older Woman/Younger Man, Oral Sex, Polyamory Vee, Post-Graduation, Riding, Romance, Stiles Stilinski Has a Big Dick, Voyeurism
Language: English
Status: Completed
Published: 2017-02-21
Updated: 2017-02-21
Packaged: 2018-09-26 02:14:00
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,874
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9857426
Author URL: https://archiveofourown.org/users/Inell/pseuds/Inell
Summary: Stiles is having magic trouble, so Derek calls in Marin to assist. It’s only a little weird asking Stiles’ other partner to come help their boyfriend, but Derek can handle their unusual dynamic.





	

**Author's Note:**

> Anonymous said: Can I throw an odd little ship for your teeny fic prompts? I'm curious to see how you'd write Stiles/Derek/Marin.
> 
> Nonnie, nonnie, nonnie. Nothing teeny about this fic at all. Teeny Fic #19
> 
> Baby, when I look in your eyes, I go crazy  
> Fever's high with the lights down low  
> So, take me over the edge
> 
> Make me lose control
> 
> Make Me Lose Control by Eric Carmen

 

It’s incredibly frustrating to want to help but to have no idea what to do. Derek never really learned a lot about magic because his family really only talked about druids, who they felt were impartial and trustworthy. He has his own opinions of Alan Deaton, and those two words don’t really fit any of them. His mom had trusted Deaton, and she’d just listened to the belief that other kinds of magic were dangerous and unpredictable. So he and his siblings had been taught to avoid magic users because of the risk.

It turns out that Deaton is the one who distrusts other magic users. It’s not a community wide standard in the supernatural realm. Sure, there are some people who abuse their gifts and use magic for ill-will, but there are many creatures who do the same. Not to mention the humans who could wear the label of monster with ease. His dislike of Deaton is supported by Stiles, who is much more vocal about it than Derek. Derek keeps his opinions to himself mostly, learning a long time ago that it’s better not to alert potential enemies to your suspicions.

Still, when Stiles graduates high school and decides he’s going to finally start researching the natural magical gifts he’s displayed signs of having, Derek is relieved when Stiles confides that he’s going to Morrell instead of Deaton. Derek doesn’t trust her, either, but she did at least make a concerted effort to help Scott and the pack despite being the Alpha pack’s emissary. She displayed an inability to remain impartial when faced with a moral choice, unlike her brother, who Stiles seems convinced knew about Kate Argent and everything that was happening with Derek _while_ it was happening.

Derek’s only been back in Beacon Hills for six months, arriving in time to see Scott, Stiles, Lydia, and Malia graduate high school. In that time, Scott has now gone to UC Davis, Lydia’s moved to Boston to attend MIT, Malia’s entered into a mechanics program where she’s showing all the chauvinistic men how good a woman can do their job, and Stiles has deferred his admission to George Washington in order to spend the required time apprenticing, which is two years. He’s taking basics at BHCU, acing the classes without even having to study much, which is good considering the amount of time he’s spending learning how to control his magic.

A little over a month ago is when things changed between him and Stiles.

They’ve been spending a lot of time together since Stiles’ other friends are off at college. Malia drops by, too, but she’s working and going to school, so her free time is pretty limited. That means that it’s usually Derek and Stiles hanging out. There’s always been something between them, a connection of some kind, but it’s never really been the right time to explore it. Stiles was too young, Derek was too fucked up, there were girlfriends in the picture or threats to the pack, but things are quiet now. That’s the reason Derek figures they both sort of decided that it’s finally the right time.

Things are going well with their relationship. It reminds him of his parents, the way they just fit together so well and complement each other and balance each other out. They have a way of smoothing out each other’s edges. Not to mention, the sex is great. Derek’s been with guys before, back in New York, but Stiles is the first one he’s ever dated. So the cuddling after sex is new to him, not something any of his previous partners has been into. Neither is the way Stiles touches him sometimes, like he’s precious treasure that has to be handled gently and have hours spent just making him feel good.

The Morrell issue isn’t nearly as bad as Derek first thought it would be, either. He’s known from the beginning that Stiles and Morrell are fucking. He could smell the sex on Stiles after every magical lesson, and Stiles hasn’t ever kept it a secret. It’s not about an emotional connection, not like what he and Stiles have together, so Derek’s surprisingly been able to accept it without feeling jealous or possessive. It’s just sex, and Stiles doesn’t lie to him about any of it, even admits the times when she goes a little soft-eyed and wants to snuggle.

There are definitely emotions involved, in Derek’s opinion, but not threatening ones to his relationship with Stiles. Stiles never makes Derek feel like anything other than the love of his life and his possible future, so he doesn’t really care that much about Stiles fucking his magic teacher on the side. It’s never flaunted around him, and he knows, in his gut, that Stiles would stop immediately if he ever thought Derek wasn’t comfortable with sharing him physically.

Tonight is the first time he’s even been around Morrell since the alpha pack drama. He’s seen her when he’s dropped Stiles off at her house or when he’s picked him up. There’s been a slight wave and amused smirk aimed in his direction. There might have been a few cases of flashed eyes and a hand firmly placed on Stiles’ shoulder to remind her he’s Stiles’ primary choice. But they haven’t actually interacted at all until he called her to his loft tonight.

Stiles is having magical trouble, burning up and sweating like he’s got a horrible fever, and Derek doesn’t know how to help. That’s where his frustration comes in, having to call Stiles’ other lover for help. Not being able to do anything but watch Morrell examine Stiles and engage in some magical whispering that makes no sense to Derek. Standing here impotently, seeing whatever she’s doing start to alleviate some of Stiles’ pain and losing himself in thoughts about why he shouldn’t feel threatened by some magical link he can’t be part of anyway.

“His magical needs an outlet,” Morrell says finally, looking up at Derek. “He had mid-terms this week, didn’t he?”

“Yeah. Two of the classes were killer, according to him,” Derek tells her quietly, not sure what magical outlet means. “He got pretty consumed studying because he refuses to get less than A’s at a community college.”

“Stubborn ass,” she mutters, looking at the ceiling as if praying for patience to deal with Stiles, which is an action that Derek recognizes, that makes his lips twitch slightly.

“You know Stiles,” Derek says, a little cautiously because he’s not sure how well she does know him or if it’s just about the sex for her.

“I do.” She smiles at Derek, looking him over. “You have no need to fear my relationship with him, Derek. You’re the one he loves. We have affection for one another because a bond forms between teacher and apprentice, and we have sex because we’re both consenting adults. If that aspect ever interferes with your relationship, it will cease immediately. He’s made that very clear, and I have no intention of protesting.”

“I’m not worried,” he tells her honestly, but there’s a part of him that feels better hearing it from her. He looks at Stiles, lying on the bed sweating, finally unconscious because of whatever Morrell did to help him, and smiles. “It’s not like I don’t understand people falling in love with him and wanting to be with him. He’s special.”

“Yes, he is,” she agrees. “Derek, his magic has basically stockpiled, for lack of a better word, due to his obsession with acing his mid-terms. He didn’t practice any of our exercises this week, and he’s been increasingly more active as our training progresses, so his magic is causing the fever and discomfort. He needs to let it out in a harmless way.”

“Alright.” Derek frowns at her, not understanding but confident that she’s going to explain it to him. “What does that mean?”

“I think you may need to call me Marin now,” she says simply, walking back over to the bed and kneeling on it. “While I can do this myself, it would be faster if I had your assistance. Your feelings for Stiles will also help ground him when the magic begins to be released.”

“I’m not following,” he reluctantly admits, biting his bottom lip as he watches her open the bag she brought with her. It’s some kind of paints, or magical stuff that’s similar. She opens one jar, a sweet scent filling the air, then she’s dipping her fingers into it and drawing designs on Stiles’ sweat-slick chest.

“Sex magic is one of the most powerful outlets for magic build-up.” She looks at him and arches a brow. “I assume you understand what I mean now?”

“You want me to have sex with him? When he’s unconscious?” Derek shifts his weight from foot to foot, gnawing on the inside of his cheek as he stares at Stiles. “Is it the only way to help?”

“He won’t be unconscious. I refuse to perform such a ritual without his full consent, especially considering our unique relationship,” Marin says firmly. “However, I need your consent before I awaken him to begin. And Derek? It won’t just be you.”

“Oh.” Derek stares at her, looking for any sign of dishonesty or deceit. Her face is open, an underlying affection for Stiles evident in the way her fingers caress his chest, but nothing posing a threat to him or Stiles. “Okay. I’ll do it. I mean, I’ll help.”

“Good.” Marin smiles before she opens another jar, drawing more designs on Stiles’ chest. “It would be beneficial if he would agree to tattoos, but his fear of needles outweighs his concern for magical balance. Perhaps if you speak with him about it…”

“I don’t know if I could convince him otherwise. Stiles is pretty stubborn,” he says, smiling slightly as he walks over to the other side of the bed. He sits down and takes Stiles’ hand in his, feeling how warm his skin in and worrying, just a little. “But I can try.”

“He’s incredibly stubborn and determined,” Marin agrees, wiping her fingers on a cloth she removes from her bag. She whispers some words in a foreign tongue that he doesn’t recognize then Stiles is gasping, his eyes fluttering as he stares up at them. “You’ve been a bad boy, Stiles. You’ve neglected your exercises, and now your magic is overheating you.”

“Sorry. Didn’t mean to, Marin. Was studying and lost track of time.” Stiles is licking his lips, and Derek reaches for a bottle of water that he set on the bedside table earlier. He tips it against Stiles’ mouth, watching him gulp down half the bottle at one time.

“I’d like to perform a ritual to allow a positive release of the stored energy. Derek has agreed to assist,” Marin explains, brushing her fingers along the curve of Stiles’ jaw. “Your consent is required before we begin.”

“Consent?” Stiles looks from her to Derek and back again before his eyes widen. “Oh. _That_ kind of ritual? Both of you? Fuck.” He nods his head eagerly. “Yes, God yes. I consent a million times over.”

“Don’t sound so reluctant,” Derek says dryly, leaning down to kiss Stiles lightly because he’s already sounding more like himself. “You’re so hot.”

“I know. I’ve told you that before but you never listen,” Stiles mutters, lips curving into a smug smile.

“Derek, if you could take his pants and underwear off, we’ll begin,” Marin says, leaning down to press a kiss against the corner of Stiles’ mouth before she whispers more magical stuff.

While she’s doing the mumbo jumbo magic stuff, Derek tugs Stiles’ basketball shorts down. He isn’t wearing any underwear because he’s been so feverish that he didn’t really want to wear anything. The shorts were hastily pulled on after Derek called Marin for help. He’s not entirely sure what to do, but he figures there’s no harm in leaning down and nuzzling Stiles’ flaccid cock. Even soft, it’s big, and Derek feels his mouth water, just a little, because he wants to suck on it.

“You can take it in your mouth, Derek.” Marin stares at him, a faint smile on her face. “There is no specific process to follow for the sex. We want him to come, and he’s going to channel his magic so that he basically sweats it out.”

“Are you planning to watch?” Derek asks, looking into Stiles’ eyes as he tries to decide how he feels about that possibility. Stiles waggles his eyebrows at him and leers playfully, which makes Derek snort a laugh.

“If you’d prefer that I don’t, I can find other means of distraction,” Marin tells him, moving her fingers over Stiles’ mouth. Yeah, he’s heard about that, knows all about how much she likes riding Stiles’ face and gets off on his oral fixation.

“I don’t care if you watch,” he decides, straightening up and pulling his t-shirt over his head. He stands up, unfastening his jeans and arching a brow when he feels two sets of eyes on him. He can feel the tips of his ears warming up at the sudden rapt attention, but he finishes getting them undone and shoves them down his legs.

“Stiles has told me a lot about you, and it’s nice to see that he wasn’t exaggerating.” She winks at Derek, basically confirming his suspicion that Stiles talked about sex with Derek as much as he talked about sex with Marin to him.

“I told you he’s gorgeous, like a perfect man sculpted out of flesh and bone by the gods,” Stiles murmurs, staring at Derek hungrily. “You gonna make me come in your greedy mouth, Der? Or maybe you want it in your ass?”

“Stiles!” Derek ducks his head, fully aware that his ears are probably bright red because Stiles it talking that way with Marin _right there_.

“You’ll be able to do both, without a doubt,” Marin says, undressing efficiently without caring that she’s being watched. “Your magic build-up is at dangerous levels, which means we _will_ be discussing this at your next lesson along with appropriate releases even during times of emotional stress.”

“Okay. Yeah. I get it. I was stupid,” Stiles says, sighing as he looks sincerely guilty for a moment. Then he’s making grabby hands at Derek and leering. “Can we get on with the sex now? I’m burning up, and I’m ready to release some of this.”

“You’re ridiculous,” Derek mutters, tone fond as he pushes his underwear down and steps out of them before crawling between Stiles’ legs. He arches a brow and smiles smugly when he stares into Stiles’ pretty eyes. “I’m going to make you lose control, babe.”

“Counting on it, Der,” Stiles murmurs, biting his lip as Derek licks the underside of his cock. It’s no longer flaccid, hasn’t been since Derek started undressing, and it starts to harden even more as Derek strokes it. He can’t take the whole length, not when Stiles is fully hard, but he can get most of it without choking. He knows Marin can take it all, no gag reflex to choke her, but it’s not a competition. Stiles loves having Derek suck his cock, and that’s all that matters.

Marin crawls onto the bed naked, her body objectively attractive and the heat in her gaze as she stares at Derek sucking Stiles’ cock nearly as hot as Stiles’ feverish body. When she straddles Stiles’ face, she does facing Derek, obviously wanting to keep watching. Stiles starts slurping and licking, making it louder than it needs to be, probably aware that each lick and slurp has Derek’s cock hardening a little more.

It doesn’t take Stiles long at all before he’s bucking up and spilling into Derek’s mouth. Under other circumstances, he’d probably be hearing Stiles bitch about shooting off like a horny thirteen year old just discovering what his dick’s for (Derek’s heard that comment multiple times over the last few weeks since they started having sex), but his words would be muffled by Marin, who is riding his face like she’s at a rodeo.

Derek watches her breasts bounce as she moves her hips, her eyes half-closed and her lips parted, quiet noises gradually increasing as Stiles moves his hand, using his fingers and his tongue on her. Stiles is still half hard despite just coming, so Derek reaches for the lube in his bedside table. He flicks the cap, squirting some onto his fingers before reaching behind him, dragging his wet fingers across his hole. Normally, Stiles would prep him, take his time licking Derek open, getting him close then pulling back, finally using his fingers and lubing him up so he could take Stiles’ cock. Since Stiles is otherwise occupied right now, Derek prepares himself.

When Marin comes, he’s got three fingers buried in his hole up to the knuckles, not quite as thick as Stiles but enough to stretch him for the real thing. Stiles is starting to cool off, his body no longer so hot it practically burns to touch. Marin is breathing heavily as she moves off Stiles’ face, and Derek watches her kiss him, licking her own release from his lips. It’s hot, which isn’t something he really expected to think.

“Der, c’mon,” Stiles whines when he pulls back from the kiss. “Need you. Wanna feel you tight around my dick.”

“Say please,” Marin says, lightly scratching Stiles’ nipples, knowing the exact way to tweak them to have him moaning low in his throat. “Bad boys have to ask nicely for what they want, Stiles.”

“Please, Derek. Please let me fuck you,” Stiles murmurs, bucking his hips up and staring at Derek with those hungry eyes.

“Go slow. I can’t prep myself as well as you do,” Derek tells him, moving to straddle Stiles’ hips. When he reaches down to grip Stiles’ cock, Marin’s hand is already there, stroking lube over it and getting it ready for Derek’s ass.

“Let me help, Derek,” she says softly, smiling at him as she guides Stiles’ cock to his hole. The head starts to press against him, and, despite all the prep, it’s still so big that it makes Derek’s eyelashes flutter as his eyes roll back when it first penetrates him. “That’s a good boy. Take it all, let him fill you up.”

“Feels so good,” Stiles whispers, reaching out and stroking Derek’s chest, tugging lightly on his chest hair before stroking his abdominal muscles and finally reaching his hips. Derek bounces slowly, taking a little more each time, feeling soft fingers slide along his spine, words of encouragement a warm breath against his ear.

Finally, he’s fully seated. He groans low in his throat as he just sits there, letting himself adjust, leaning forward to kiss Stiles when he’s ready to start moving again. They’re so good together, knowing exactly what each other need, giving and taking and sharing. Derek feels the heat in Stiles’ body all around him, searing him, claiming him, and then it starts to fade, cooling down, becoming more normal, but the sex is still so intense. There’s magic in the air, surrounding them, and he feels Marin watching but doesn’t care.

Likes it, in fact.

Showing off for someone else, letting them see how fantastic he and Stiles are for each other, knowing they must be sensual and arousing to watch because he knows how they look, how they are together. It makes his inner wolf preen, especially since it’s someone watching who has their own claim on Stiles, able to see that he’s the one who can give this to Stiles, the one who makes him feel this way: safe and loved and wanted and cherished and desired.

It’s so intense that it’s making him grapple with his control. Stiles is the one who’s supposed to lose it, not Derek, but he’s the one feeling his teeth itch as his fangs press forward, feeling his fingers flex as his nails grow into claws, feeling his face shift as his wolf comes forward. When Stiles strokes his cock and whispers words of love and devotion and want in his ear, Derek can’t hold it back. He comes with a low growl, his teeth piercing Stiles’ shoulder hard, the taste of bitter copper on his tongue as he shudders.

At some point, Stiles has also come. His cock is pulsing, spurting come into Derek’s ass, filling him up as they tremble and shake. The scent of sex and sweat and magic is a heady aroma, filling the room, spreading out into the entire loft. Derek gradually starts to come back to himself, pulls his mouth off Stiles’ shoulder and kisses the bite mark he’s made. There’s a damp cloth moving over his sweaty back, gentle hands wiping his face and hair, the scent of magic stronger as Marin cleans them off.

He still doesn’t trust her, still isn’t sure what she’s really getting out of all this, still isn’t sure he likes Stiles learning from her, but she’s proven tonight that she has Stiles’ best interests at heart. In the grand scheme of things, that’s all Derek really cares about. Stiles having someone who can teach him what he needs to know about magic that prioritizes his health and safety above the power and skill.

Stiles is passed out, exhausted from the magic fever and the rather strenuous sex magic. It’s a natural exhaustion, though, and he’s snoring softly, mouth hanging open, features relaxed and calm. The fever’s gone, his body a normal temperature now, still sweaty and warm, but due to sex and Derek covering him with his overheated body not because of magic. Marin cleans off the designs that are now smeared on both their chests when Derek pulls off Stiles’ spent cock, moving beside him and holding him close, watching her intently.

“He’s going to be fine, but we need to encourage him to get the runes tattooed on him, and I _am_ going to lecture him during our next lesson about taking better care of himself,” she murmurs, dropping the damp rag on the floor before picking up her clothes. She gets dressed just as efficiently as she got undressed, smiling when she’s finished. “I’ll see myself out. Stay with him. Make sure you give him plenty of water and that he eats something substantial this evening.”

“Thank you,” Derek whispers, meeting her gaze fully. There’s a slight flicker of surprise that she carefully conceals, and she just nods at him. “I’ll let you know how he’s doing, and I’ll work on the tattoo thing.”

“It’s been a pleasure, Derek.” Marin reaches out to stroke Stiles’ damp hair. “Take care of our boy.”

She winks at him before she heads downstairs. He hears the clicking of her heels on the floor then the door opening. After it’s closed, he hears it lock, his lips twitching slightly because she must have used magic to make sure it locked so that no one could get in to harm them. Derek pulls Stiles closer, ghosting his lips across the bite on his shoulder, before he murmurs, “I’ll take good care of our boy.”


End file.
